A Defense Department review of criminal investigations into sexual assault found deficiencies in 72 percent of the cases, but only 11 percent of the cases had what were considered “significant” errors or omissions requiring more investigative work, according to a Pentagon report released Monday.

Significant deficiencies included not collecting key evidence or losing the evidence; not conducting thorough witness interviews; and not re-interviewing the victim, witnesses or the accused when new information was uncovered, according to the report from the Defense Department inspector general, based on a review of 505 closed cases from 2010.

Of the 56 cases returned by the IG for further investigation, 31 were reopened, the report says. It does not disclose the outcomes.

The report provides advice to the services suggesting they do a better job at the start of investigations in collecting physical evidence, such as clothing, DNA samples, and records of telephone calls and texts that can end up playing a key role in the outcome of a case.

Investigators said they observed incidents when the victim’s clothing and cell phones were not collected and DNA was not collected from suspects.

All of the service criminal investigative agencies had similar problems, according to the report.

The services use slightly different procedures, the IG noted.

The Army Criminal Investigative Division requires collection of the victim’s clothing but not the clothing of the accused or any clothing a victim might have put on after a rape or assault.

The Naval Criminal Investigative Service advises but does not require collection of clothing from the victim and accused, leaving discretion to investigators about the potential value as evidence.

The Air Force Office of Special Investigations policy “does not address the collection of articles of clothing the subject or victim might have placed on themselves immediately following an assault, if that clothing was something other than what the victim or suspect wore during the assault.”

The three criminal investigative agencies agreed with the substance of the report, although they quibbled with some of the details.